The Zig-Zag arrangement is canceling itself out...
I will be honest, your antenna looks a lot like one I created when I first got started at 12yo. Lots of wire, every which way, it did not work...
I would:
Decide which location is better suited for radio operation, I am assuming it is the red boxes, choose one...
Then choose the farthest , high mount point for the far end as high and as safely as possible.
Chose the other end such that, in the building arrangement, permits the far antenna wire to pass over the point where the radio is. Anchor at that point and fasten a "downlead" at that end.
Never place the antenna above or below power lines...
For BC band it is better advantage to have some height to the antenna wire as the vertical wire does a lot of pickup as well so long as it is 90 degree as much as possible to the horizontal wire.
DO use glass or porcelain insulators for the ends of the antenna, fasten the down lead with a small bronze clamp. The highest voltage on an antenna is at the ends, so any leakage, poor insulators, dirty insulators is important for a crystal set. Avoid plastic, it has an electrostatic attraction for dust. If you are stuck for antenna insulators PM me... There are compression type or strain type. If a strain insulator breaks, the antenna will fall but strain type has longest leakage path. A compression type never seems to break and the loops hold it together, but the leakage path is short and they are somewhat hard to clean. Compression insulators are better for guy wires...
Change the ground rod to as near to earth and the "window" location of the radio. DO buy an 8 foot rod, it will be hard to drive in depending on how far from the foundation of the house, usually some 3' away will be clear of the concrete footing WARNING if even the slightest doubt that there is buried utilities call DIG-SAFE and find out...
That "new" ground rod can be driven below grade and attached using bronze electrical clamps #10 or larger wire and bury too. Direct the larger ground wire to the wall of house that wire can be now changed in size to a smaller easier to manage ground wire, use another bronze clamp and run as direct as possible to the window entrance. Do keep this ground arrangement as short as possible.
Do not connect either the ground or the antenna download to anything else except a lightning arrestor and the radio...
Those bronze clamps can be coated with asphalt roofing cement for weather protection. "Tar" coating can be cleaned off later if need be and will last some 10 or more years.
Those bronze clamps are called "Burndy" or "Burndies"
Attachment:
Burndy clamp.jpeg [ 22.14 KiB | Viewed 295 times ]
Burndies come in ALL sizes, small for two/three #18 wires up to two #0000 cables, yes I have installed Burndies on mill "cleat" lines. Its an all day project for a three phase line... The big Burndies require 24's (24" wrenches) to tighten
Antenna installations should not be soldered, soldering anneals the copper and makes a weak point where the antenna will stretch and break.
Ideally, antenna wire for receiving or low power transmitter is between #14 to #18 ga hard drawn strand (usually 7 strands).
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There are at least two "things" going on that are causing reception of one station all over the dial. The crystal set selectivity is poor, combined with the strong signal. To reduce the strong signal a "Wave Trap" is used, it is a tuned circuit that is either put in series or parallel and can be series or parallel in configuration. Generally it is made from an inductor and a variable condenser that can tune the all or a portion of the radio band desired, just like a crystal set does, but the coil is given consideration design for high "Q"... Once the wave trap is connected, it is tuned to reduce the offending signal. The wave trap does reduce the overall signal but the reduction of the offending signal is significant.
I advise learning how to make more efficient coils, in any style you choose. Do look carefully at the use of litz wire, it is pricey, hard to terminate and effectiveness over solid wire is marginal Often, litz wire coils are the last step in efficiency in a crystal set.
GL
Chas